RESUMEN
To explore the influence characteristics of the interaction effects between meteorological factors on ozone(O3) concentration in Chengdu, daily air pollutants and meteorological data from 2014 to 2019 were collected. Generalized additive models(GAMs) were adopted to explore the effects of different factors on O3 concentration. The results showed that the relationship between O3 and maximum temperature, sunshine hours, relative humidity, wind speed, precipitation, maximum mixed depth(MMD), and ventilation coefficient(VC) was non-linear. Specifically, the maximum temperature, sunshine hours, MMD, and relative humidity had a significant influence on O3 concentration throughout the year. It is worth noting that the influence of relative humidity and precipitation on O3 concentration during summer was more significant than that for the whole year. In the multi-meteorological factors GAMs of O3 concentration, the meteorological factors mentioned above, except average wind, had significant impacts on O3 concentration change. For the whole year, the judgment coefficient(R2) was 0.849 and the variance explanation rate was 85.1%. The maximum temperature was the most important influencing factor on O3 concentration throughout the year. During summer, corresponding R2 was 0.811 and the explanation rate of variance was 81.3%; however, maximum temperature and MMD were the dominant meteorological factors. In the interaction GAMs, for the whole year, the interaction between maximum temperature and sunshine hours, relative humidity, and precipitation, and the interaction between sunshine hours and MMD had a significant impact on O3 concentrations. The interaction between maximum temperature and sunshine hours played a leading role in changes of O3 concentration. The high temperature+strong radiation+MMD(about 2000 m) +no precipitation were conducive to the formation of O3 concentration, but in summer, only the maximum temperature, sunshine hours, and VC had the most significant effect on the O3 concentration, and strong high temperatures+strong radiation+the little horizontal wind in summer were conducive to the formation of O3 concentration near the surface. In summary, GAMs model can not only be used to identify the dominant influencing factors of O3 pollution, but also quantitatively analyze the influence of single effects and interaction of influencing factors on O3 concentration, which has great significance for the prevention and control of O3 pollution.
Asunto(s)
Contaminantes Atmosféricos , Ozono , Contaminantes Atmosféricos/análisis , China , Monitoreo del Ambiente , Conceptos Meteorológicos , Ozono/análisis , Estaciones del AñoRESUMEN
BACKGROUND/AIMS: The Hippo signaling pathway regulates expansion and differentiation of stem cells and tissue progenitor cells during organ development and tissue regeneration. Previous studies have shown that YAP1, a potent effector of the Hippo signaling pathway, plays a crucial role in pancreas development, but the function of YAP1 in pancreatic progenitor cells is less known. METHODS: The spatio-temporal expression pattern of YAP1 in mouse developing pancreata was detected by in situ hybridization. The effect of silencing YAP1 on the proliferation of pancreatic progenitor cells was analyzed by CCK-8 assay and Ki67 immunostaining. The regulation of miR-375 on YAP1 expression was determined by dual luciferase reporter assay, QRT-PCR and western blot. Finally, the influence of miR-375 on proliferation of pancreatic progenitor cells was analyzed by CCK-8 assay and Ki67 immunostaining. RESULTS: We found that YAP1 was highly expressed in embryonic and adult pancreatic progenitor cells. Knocking down YAP1 by siRNA inhibited the proliferation of pancreatic progenitor cells. The mouse YAP1 was a target gene of miR-375, and miR-375 could target the 3' UTR of YAP1 mRNA to decrease its protein and mRNA levels. Similar to silencing YAP1 by siRNA, the proliferation of pancreatic progenitor cells was inhibited significantly by miR-375. CONCLUSION: Our results indicate that YAP1 is necessary for the proliferation of pancreatic progenitor cells and miR-375 participates in regulating YAP1 expression during pancreatic progenitor cells differentiation.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/metabolismo , MicroARNs/metabolismo , Páncreas/citología , Fosfoproteínas/metabolismo , Células Madre/metabolismo , Regiones no Traducidas 3' , Células 3T3 , Proteínas Adaptadoras Transductoras de Señales/antagonistas & inhibidores , Proteínas Adaptadoras Transductoras de Señales/genética , Animales , Secuencia de Bases , Proteínas de Ciclo Celular , Proliferación Celular , Células Cultivadas , Ratones , Páncreas/patología , Fosfoproteínas/antagonistas & inhibidores , Fosfoproteínas/genética , Interferencia de ARN , ARN Mensajero/química , ARN Mensajero/metabolismo , ARN Interferente Pequeño/metabolismo , Alineación de Secuencia , Células Madre/citología , Proteínas Señalizadoras YAPRESUMEN
An efficient and metal-free oxidative method was reported for synthesis of triply linked diporphyrins with 2.5 equiv of phenyliodine bis(trifluoroacetate) (PIFA). This reaction showed high selectivity for Zn(II) porphyrins and had been successfully applied in the synthesis of a novel triply-singly interlacedly linked porphyrin array with lower energy gap.
Asunto(s)
Fluoroacetatos , Compuestos Organometálicos/síntesis química , Porfirinas/química , Yodobencenos , Estructura Molecular , Compuestos Organometálicos/química , Oxidación-Reducción , Estereoisomerismo , Ácido Trifluoroacético/química , Zinc/químicaRESUMEN
Diastereoselective syntheses of meso-meso linked diporphyrins were achieved via intramolecular chiral induction. The structures and conformations were analyzed by CD, UV, NMR, and computational calculations.
Asunto(s)
Metaloporfirinas/síntesis química , Porfirinas/síntesis química , Espectroscopía de Resonancia Magnética , Metaloporfirinas/química , Modelos Moleculares , Estructura Molecular , Oxidación-Reducción , Porfirinas/química , Espectrofotometría Ultravioleta , Estereoisomerismo , Zinc/químicaRESUMEN
Vasoactive intestinal peptide (VIP) is one of the most important sensory neuropeptides in respiratory system. We previously reported that VIP enhances wound healing and proliferation of human bronchial epithelial cells (HBECs), and these effects are mediated by intracellular signaling molecules such as protein kinase A (PKA), protein kinase C (PKC), Calmodulin (CaM), and extracellular signal-regulated kinase (ERK). In the present study, we further investigated the role of cAMP Response Element Binding Protein (CREB) in VIP-promoted protective effects in mechanical-damaged HBECs. VIP-mediated wound healing and cell proliferation in HBECs was inhibited by CREB antisense oligonucleotides (ASO) in a time-dependent manner. VIP increased the CREB DNA binding activity and expression of the p-CREB that were inhibited by VIP receptor antagonist. Increased CREB DNA binding activity and expression of the p-CREB were also partially inhibited by PKA and ERK inhibitors. These results suggest that the VIP-mediated wound repair of HBECs is associated with activation of CREB via PKA and ERK dependent pathway.